Not entirely true. I've ran/owned two (I'm approaching 40). If you find the right opportunity, you can make a very nice living. Never had an investor and I grew up very poor. Of the few brick and mortar businesses left that can make money, a food business is certainly one.
It's 7 days a week work and it never stops coming at you but if your sensible and a hard worker, you can certainly make a nice living. 90% of restauranteurs fail bc they live above their means and are poor money managers and can't manage people or business expenses. Plain and simple.
Manage your food cost, find a nice lease or better yet, buy the space (easier said then done these days). Make it a one or two man operation, counter-type service in a blue collar, working man's area. A food truck as you mentioned also viable if the market isn't already saturated. You just have to be smart about it and most don't have a f ING clue.
I'm a single dad to a 7 year old and don't want to miss out on anything w my little girl, otherwise I wouldn't hesitate to own a small restaurant again. As I said, it isn't glamorous, and it's full time, 7 days a week. But, 80-125k net after operating expenses is fairly easy if you're smart about it. It's just most people don't have the business sense or capabilities to understand what and where.
It's not a terrible idea at all for those w common sensibility and who can cook there asses off... great food, good portions and served at a fair price in working class area can and will clear some nice cash.